Keeping ACC Green

Building it right, is only the start, when it comes to energy efficient buildings.

When the Ambulatory Care Center (ACC) opened in 2010 it earned LEED Silver from the U.S. Green Building Council, making it the first building on campus to be recognized for sustainable design. But keeping buildings green requires vigilance and fine tuning. A recent project to optimize the building’s complex operating systems yielded significant savings, reducing airflow in the building by 40 percent.

“The newer the building, the more sophisticated the systems, and it takes a lot of work to make sure they are running efficiently,” said Bill Gnerre, CEO and cofounder of Interval Data Systems (IDS), the firm engaged by the medical school to study the ACC building systems.

Gnerre and his team have developed specialized algorithms that take data from a building’s control system and use the information to identify issues that are causing the building to consume more energy than expected. At the ACC, Gnerre’s group sampled 4,000 points within the building control systems, every 15 minutes, for several months. Those “points” can be thermostats, valve positions, air flow settings, equipment set points, and so on.

Numerous operational issues were identified, including minor mechanical issues that are not readily visible to the eye, but are identified through data analysis, like dampers inside ductwork that were stuck in one position, or valves that were not working properly. “This was an important project, because it helps our operating engineers identify issues that cannot be seen through regular inspections,” said James Gardner, director of facilities maintenance, at UMass Chan.

The IDS review also found that the building management system was not optimally adjusting HVAC flow for “occupied” versus “unoccupied” times of the day. They also found instances where the building’s systems were competing with each other, using more energy than needed trying to heat or cool a space simultaneously.

“There was a conference room, that turned out to be supplied by two terminal units, and they were fighting each other,” Gnerre said. “One side of the room was always too hot, the other side too cold.”

After digesting all the data, and working closely with Gardner’s team to make repairs and adjustments, the project reduced the amount of airflow in the building by 30 percent while still meeting health and safety standards.

“That’s a lot less air you have to heat or cool, so it’s a major savings,” Gnerre said, noting that the school also received some energy savings rebates for the project from the utility.

Built by UMass Chan Medical School in collaboration with its clinical partner the UMass Memorial Medical Center, the 253,000 square-foot ACC is home to a mix of patient-care, clinical research and educational activities.

To meet the high standards required for LEED Silver certification, numerous sustainable features were integrated into the ACC. For example, the building’s design and orientation helps prevent solar heat gain, thereby lowering the need for mechanical cooling. The building has a white roof to diminish the “heat island effect” and reflect rather than absorb heat; a tight exterior building envelope with tinted, reflective and insulated glass; and an east-west building orientation to minimize the number of south-facing windows.